High tension transformer



Feb. 21, 1933. K. BAHRMANN 1,898,931

HIGH TENSION TRANSFORMER Filed July 14, 1930 2 sheets-sheet 1 @S @gm o frcs.

Feb. 21, 1933. f K. BAHRMANN 1,898,931

HIGH TENSION TRANSFORMER Filed July 14, 1930 2 Sheets-Sheet 2 @ri/L Patented Feb. 2l, 1933 UNITEDA sTATEs PATENT OFFICE DRESDEN, GEBIANY, ASSIGNOB T KOCH t STEBZEL AKTIEN- 0l' DRESDEN, GERMANY, A COHPANY QF GERMANY HIGH TENSION TRANSFOBIEB Application mea my 14, mso, semi no.

My invention relates to transformers, and particularly to hi h potential transformers of the type in whic the high potential winding consists of disc-windings arranged on a unitary spool. It hasbeen found that, with a layer-wise winding arranged in a unitary insulating spool box and so connected that the potential increases from the outermost layer towards the core, the commencement of the innermost windin being uided throu h the flange of the spoo box, oi' insulation or the windings of the transformer is not essential. v

The object of this invention is to provide a transformer having disc-shaped windings which has the advantage that oil insulation for said windings is unnecessary and, to achieve this result, the spool body surrounding the iron core is formed of two insulating concentric annular tubes, said tubes being bridged at one end to form an annular recess so that the whole constitutes an insulating body'of substantially U-shape in cross-section which is made up of two concentric tubes each having one edge joined to the adjacent edge of the other or which may have their edges at one end joined. The windings are inserted into the recess through the open end thereof, the winding end adjacent the bridged or closed end being led out through an insulator formed integrally with the spool body.

As in this type of transformer the potential increases in the direction of the axis of the windings, the annular recess within which said windings are housed may be tapered inwardly towards the winding end carrying the higher tential, the several disc windings gradual y decreasing in size in the same direction. This arrangement provides for a reduction of the short circuit potential and also for the building of a very compact transformer.

A further feature of the invention resides in the fact that two unitary spool bodies of the type disclosed may be telescoped one within the other whereby .the lead-out insulators are dis d on opposite sides of the transformer, w 'lst both poles may be insulated from earth.

In the drawings,

Figures 1 and 2 show vertical sectional 461,900, ma in ormany my a7, 1m.

Figure 8 shows the method of suspending a transformer of the pillar type having an 1nsulated iron core.

Around the core 11 there is disposed the secondary .winding 12 surrounded by a unitary insulating body consisting of a pair of concentric annular tubes 13, 14 bridged or closed at one end as at 15 and a lead-out insulator 16. In the recess between the two tubes 13, 14 are located the individual disc windings 17 and between each of said windings there is arranged an insulating disc 18. These discs are formed as annular ribs on an insulating tube 19 surrounding the inner tube 13 of the spool so that the high potential winding may be assembled outside the spool body and then bodily inserted into the recess. It will be seen that by reason of the present arrangement of arts there is rovided an insulating body o? inverted -shaped cross-section which is made up of two concentric tubes each having one edge joined to the adjacent edge of the other.

The commencement 20 of the high potential winding is placed upon the earthed iron core 11 so as to be electrically connected thereto, whilst the other end of the winding is connected to one end of a slit metal ring 21 fitting Within the recess formed between the tubes 13, 14 and being located adjacent the closed end thereof. The other end 22 of the ring may be either connected to the leadout wire or said lead-out may be formed by an upwardly directed extension of said ring. The ring thus forms the first or input turn .0f the high potential winding. Extending the spool body and over the bridging. or closing portion 15 is a conductive coating 24 obtained, for example, by sprayed metal or graphite, such as is shown in broken lines 1n igure 2. The open or under side of the insulating body is covered by means of a plate 25 secured to the core. p

The insulator 1.6 may, if desired, be arranged to project horizontally of'the transformer whereby the structural height is substantially reduced.

In the modification s hown in Figure 3, the generalv arrangement of which issimilarto that above described, the two tubes, l13, 14 decrease in thickness towards theffopen end thereof which results in the formation of a tapered recess for the high potential winding. This tapering of the recess is so arranged that the thicker portions of the tubes lie adjacent those parts of the winding carrying the higher potential. It is not essential, however, to decrease the size of the recess in order to provide an increasing thickness of insulating wall towards the winding end carrying the high potential. Thus the outer sides of the members forming this recess tapered outwardly towards the closed end. It is also possible, by means of the closing or bridging part l5 and a flange 26 attached thereto to secure the transformer to the wall or ceiling `of a switch-house.

In Figure 4 a high potential transformer is shown in which neither of the two connecting poles reverse. In this construction two unitary insulating bodiesA 27, 28 are telescoped, one into the other, in opposite directions so that the lead-out insulators for the two poles lie on opposite sides of the transformer.

In Figures 5 and 6 there is shown a three phase transformer comprising three units of the type shown in Figures 1 and 2. These separate units are mounted on a triple shouldered iron core 30 whereby the complete transformer can be made more compact than is usual. In order, however, that the insulators 16 may be suiiiciently spaced they are arranged in somewhat staggered formation, the distances a, b being thereby increased.

Figure 7 shows the arrangement of two transformer units of the form shown in Figures 1 and 2 mounted on the arms of a twoshouldered iron core. The core is mounted on insulators and the centre of the high potential winding is connected therewith, through the open ends of each spool body to obtain a' double potential at the lead-out point.

As shown in Figure 8 the two units of a bipolar transformer of the type shown in Figure 7 can be constructed in a manner known per se to form a suspended column, the high potential windings being connected in cascade.

Thus there is produced, according to the inannular/concentric insulating tubes enclosing said winding ensure the prevention of. short circuiting voltages between non-adj acent disc windings. What I claim and desire to secure by Letters Patent of the United States is :-l

1. In a high potential transformer having I an insulated body provided with spaced outer `and inner annular walls connected at one end and open at the other, a secondary winding positioned within the inner wall and a disc- .shaped high potential winding mounted within the opening between the inner and outer walls.

2. In a high potential transformer having an insulated body providedwith spaced outer and inner tapered annular walls connected at one end and open at the other, a secondary winding positioned within the inner wall, and a disc-shaped high potential winding `within the opening between the inner and outer walls.

3. In a high potential transformer having an insulated body provided with spaced outer and inner tapered annular walls connected at one end and open at the'other, a secondary winding positioned within the inner wall,

and a disc-shaped high potential winding within the opening between the inner and outer walls, the thickness ofsaid Walls increasing towards the closed end thereof.

A 4. In a high potential transformer having an insulated body provided with spaced outer and inner tapered annular walls connected at one end and open at the other, a secondary windin positioned within the inner wall, and a disc-s aped high potential winding within the opening between the inner and outer walls, the thickness of the walls increasing towards the windingend carrying the high potential.

5. In a high potential transformer having an insulated body provided with spaced outer and inner annular walls connected at one end and open at the other, a secondary winding positioned within the inner wall, a discshaped high potenaial winding mounted within the opening between the inner and outer walls, and a split ring forming a turn of the high potenaial winding, said ring being located adjacent the closed end of the body.

6. In a high potential transformer having an insulated body provided with spaced outer and inner concentric walls connected at one end and open at the other, a secondary windingpositioned within the inner wall, an iron core extending axially within said secondary winding, a disc-shaped high potential winding mounted within the opening between the inner and outer walls and connected to said iron core, and a cover plate for the opened end of the transformer.

s In a high otental transformer having an insulated bo y provided with spaced outer and inner concentric walls connected at one end and open at the other, a secondary winding positioned within the inner wall, an iron core extending axially within said seconda winding and connected to one end of the hi potential winding, a. cover plate for t e opened end cf the body, means securing the cover plate to the iron core2 the closed end of the body having a supporting flange extending therefrom.

8. In a hi h otential transformer having an insulated o y provided with s aced outer and inner annular walls connecte at one end and open at the other, a secondary windin positioned within the inner wall and a hig potential winding mounted within the openlng between the lnner and outer walls.

KARL BAHRMANN. 

